Fan construction



May 14, 1929. p, UTER M 1,112,527

FAN CONSTRUCTION Filed Jan. 25, 1926 Fig.7.

Patented May 14, 1929.

barren STATES PATENT 'orrice.

PHILIP)? SU'ZPER, BADEN, 91WJE'TZlrilPellrAND, ASSLCGNOR TO AKTIENGESELLSGHAFT BROWN, BOVERI & (3113., OF BAIDEN, SWITZERLAND, A JOENT-STOCK COMPANY 035 EVTITZEELAND.

FAN CQNSTRUCTION.

Application filed January 25, 1926, Serial No. 83,503, and in Germany February 2, 1925.

This invention relates to the construction of fans of the centrifugal type. The general object of the invention is the provision of a fan of light construction which is a particularly well qualified to sustain the operating stresses, and at the same time susceptible of production at low cost.

Another object is the provision of a construction which is free from functional disorders.

Another object is the provision of a con struction which combines maximum strength and minimum weight.

A further object is the provision of a fan which is easily mounted on the operating member. c

Other and further objects will be pointed out hereinafter, indicated in the appended claims, or obvious to one skilled in the art upon an understanding of the present disclosure. lln the accompanying drawing forming a part of this specification I show one form in which the invention may be embodied,

Fig. 1 showing a front elevational view,

Fig. 2 a sectional View on line 2-2"0f Fig. 1, showing only part of the operating support, and

Fig. 3 a perspective view of a single blade section.

it is to be understood that this particular form is shown here for purpose of illustration only, and that the invention may be embodied in structure differing therefrom in various particulars and degrees.

Referring first to Fig. 3 of the drawing, let itbe understood that the element there shown is one of a number of complementary identical blade sections, each formed from a unitary metal blank, and having a hoop section 10 with an off-set end portion 10, and a blade portion 11 with a blade extension 11 lying in the plane of the blade and extending across the hoop section. The hoop section is formed on the desired circular arc, and a number of the elements fastened together in complementary arrangement, the end portions of the hoop sections being overlapped and united by spot welds lV. This forms a completed hoop or supporting base member or band carrying a plurality of in tegral radially extending fan blades. The hoop is welded to brackets 12 at proper intervals, whereby the device may be suitably mounted on the rotary support 14.

In the operation of a fan, reaction stresses are exerted on the radial blades by the air, tending to swing them toward. the axis of rotation, and this, in former light constructions, has distorted the blades unless they are supported at their outer ends. The arrow in Fig. 2 is intended to illustrate the general direction of these forces. By virtue of the present construction, the blades are effectively supported against these forces by the blade extensions 11, which function as stiffening struts in the reaction plane. The construction is further qualified to sustain the reaction by virtue of the fact that the line of connection of the blade to the hoop lies in the reaction plane. Thus the in-.

vcntion provides a very light and economical construction of desirable strength and stability.

What I claim is 1. A fan having a plurality of fluid-impelling blades and a supporting hoop therefor and comprising a plurality of complementary sections each made from a single piece of metal and each including one of said blades and a portion of said hoop, the sections being secured to each other and arranged with their respective hoop portions placed end toend to form and constitute said hoop.

2. In fan construction, an impeller wheel formed of identical sections, each section consisting of a hoop portion having its greater width parallel to the axis of rotation of the fan, a blade portion at one end of the hoop portion formed radially thereto, a blade extension in the plane of the blade, and an offset end portion at the other end of the hgop portion adapted to overlie the adjacent section; said hoop portion, blade portion, blade extension and offset portion being formed integrally.

3. In an impeller wheel for fans; a blade section cut integrally from sheet metal and bent to form a hoop portion, a blade portion at one end of the hoop portion and radial thereto, a blade extension in the plane of the blade portion, and an offset portion at the other end of the hoop portion.

el. A fan having a supporting hoop and a plurality of fluid-.impelling blades carradially outspect to each other and secured together at their respective adjacent ends to form and constitute said hoop, said blade portions extending radially outwardly to provide said blades and radially inwardly to provide re-en'forcing extensions for said blades.

In testimony whereof I have hereunto subscribed my name at Zurich, Switzerhnnl, on the 11th day of January, A. D. 1926.

PHILIPP SUTER. 

